Jamie Campbell Bower's interview for GQ Magazine

“Er,” says Jamie Campbell Bower, his sloth-like limbs coiling around his chair out of discomfort, streaks of blond hair pulled this way and that.

Go on, I coax. You can tell GQ. After all, the 24-year-old is now dating his daughter, Lily Collins, who is also his co-star in forthcoming teen blockbuster The Mortal Instruments: City Of Bones, which is how they met.

So, have you? “No … no … ” he squirms, not answering the pergunta so much as rejecting the question’s premise. ‘This is not about that!”

Except the “this” - their actual relationship - is very much about the “that”, which is to say, their parts in the film. Think of it like a starter-home version of the Twilight are-they-aren’t-they? saga (answer: yes, of course they are) concerning the on-screen/ off-screen romance between Robert Pattinson and Kristen Stewart. Both, after all, take the romantic leads in a supernatural teen franchise based on mega-hit books. Both have a tween army of fãs who are likely to queue for days and scream like a meteor is landing at the premieres. So yes, says Campbell Bower, “there was undeniable chemistry” when he and the 24-year-old Lily had their screen test. They had met briefly some years before, he says, at a premiere, but hadn’t kept in touch.

“Even the author,” he says, “said that when she saw it [the screen test] there was a chemistry that just jumped right off the screen. But I mean, there’s chemistry for the movie, and then my own life … ” But they’re not exactly different things, are they? “Yeah … l know. If you’ve got chemistry; you’ve got chemistry, but I try to keep who I am as Jamie quite separate.”

Good luck with that.

Not that Campbell Bower has had an easy time from the fans, even without the relationship sideshow. After smaller roles in tween juggernauts such as Twilight (where he played Caius) and Harry Potter (Gellert Grindelwald), along with the lead in one failed TV series (Channel 4’s Camelot), he does seem the perfect fit to finally make the step up and play Jace Wayland, the books’ sobrenatural sardonic demon-slaying antihero. But the fãs disagreed.

“Yeah, I’d be lying if I said the reaction wasn’t negative. People have preconceived notions of who the character should be. And then there’s someone like me who changes that.” What did they say? “Oh God, you know, ‘He’s too ugly’, or ‘He’s not butch enough’, or ‘He doesn’t work out enough’. All this shit, basically, that actually means f* * * all. Because, you know, I’m a product, effectively. I’m mais than happy to change, and put the time and effort in. You know, we weren’t shooting for another six months!”

To be fair, Campbell Bower has been on the receiving end of fã affection too - in one instance, when he was in Twilight, a little too much.

“l was sent a bondage colarinho, colar and a wheel of cheese. We were in Baton Rouge, Louisiana, and someone just left it in reception for me. The bondage colarinho, colar had nipple clamps attached to it. It was quite bizarre.”Did you eat the cheese? “No. I thought it might have glass in it or something. Or, worse, Viagra. I would be walking around with a dairy erection! It had a note too, which started por saying, I’m not a psychopath’, then detailed a lot of sexually explicit things the person wanted to do to me.”

For now, Campbell Bower has to go. He’s got a flight to catch to LA, and to Lily, a much mais healthy object of affection. His seguinte film, he says, should see him play a musician, in a movie that’s become something of a passion project for him. So if it comes off, will he consult Phil for … “No!” Worth a try.